Wiper assembly for cleaning spiral twist bits on earth drilling rigs

ABSTRACT

A wiper assembly for cleaning a spiral twist bit on an earthdrilling rig is disclosed. The wiper assembly comprises a first cylindrical tube member mounted on the drilling table of a drill rig. The first tube is mounted concentrically with the drill. A second cylindrical member is mounted concentrically with the first tube and carries, on diametrically opposite portions, pivotally mounted wiper blades. In a first position of the wiper blades, they engage the outer wall of the first tube and are clear of the bore. Each wiper blade is resiliently urged radially inwards and, when the second cylindrical member is displaced towards the lower end of the first tube, the wiper blades pivot inwards and engage the spiral twist bit of the drill. Thus, when the drill is rotated and retracted, it is cleaned by the wiper blades.

United States Patent [72] Inventors RudnlfR.G.I-Iennecke.Buuch-Grunhach;

Kraus Egon- EsslingenlNeckar 1,

Germany 1211 ApplNo 12,911

[22] Filed Feb. 20, 1970 [45] Patented June 1, 1971 {731 Assignee Delmag-Maschinenfabrik Reinhold Dornfeld Esslingen/Neckar, Germany [32] Priority Feb. 28,1969

[33] Germany [54] WIPER ASSEMBLY FOR CLEANING SPIRAL TWIST BITS ON EARTH DRILLING R168 12 Claims, 1 Drawing Fig.

1561 References Cited UNITED STATES PATENTS 386,901 7/1888 Stanley 175/84 1,220,949 3/1917 Camp...... 175/84 1,356,125 10/1920 Chattstrom... 175/84 2,000,195 5/1935 Siebel 175/313 Primary Examiner.lames A. Leppink Attorney-Nelle and Nolte ABSTRACT: A wiper assembly for cleaning a spiral twist bit on an earth-drilling rig is disclosed. The wiper assembly comprises a first cylindrical tube member mounted on the drilling table of a drill rig. The first tube is mounted concentrically with the drill. A second cylindrical member is mounted concentrically with the first tube and carries, on diametrically opposite portions, pivotally mounted wiper blades. In a first position of the wiper blades, they engage the outer wall of the first tube and are clear of the bore. Each wiper blade is resiliently urged radially inwards and, when the second cylindrical member is displaced towards the lower end of the first tube, the wiper blades pivot inwards and engage the spiral twist bit of the drill. Thus, when the drill is rotated and retracted, it is cleaned by the wiper blades.

PATENIEU-Juu nan WVENTW? RUDOLF R G. HENNECKE EGON KRAUS 711143742X; ATTORNEYS WIPER ASSEMBLY FOR CLEANING SPIRAL TWIST BITS I ON EARTH DRILLING RIGS BACKGROUND OF THE INVENTION The present invention relates to a wiper assembly for cleaning a spiral twist'drill bit on an earth-drilling rig.

In the case of earth bores, particularly in heavy soil, the boredout material no longer drops out of the drill spiral by it self. Therefore, it is-necessary to provide a device for wiping off the drilled-out material.

It is known practice to throw off the bored-out material by centrifugal force,'by increasing the rotary speed of the drill. However, this is successful only if the material is relatively loose; in addition, it constitutes an excessive loading on the drill rod drive.

It has been proposed to provide a wiper assembly comprising a tubular reamer which is pivoted laterally into the drill spiral and slides upwardly and downwardly in a guide situated at right angles to the reamer and alongside the drilling axis.

However, such known arrangements suffer from the disadvantage that the laterally located guide is a great hindrance to further drilling and lining operations.

Also, because of the bending and torsion forces to which such arrangements are subjected, the guide and the reamer have to be of a very robust form of construction and negligence on the part of the operator may result in the transmission elements being overloaded.

SUMMARY OF THE INVENTION According to the present invention, there is provided a wiper assemblyfor cleaning a spiral twist drill bit on an earth drilling rig, said wiper assembly comprising a first cylindrical tube member for mounting on a drill rig concentrically with the drill thereof, a second member slidably mounted for axial movement along said first'tube member, and at least one wiper blade pivotally mounted on said second member for movement between a first position clear ofthe bore of said first tube member and a second position to engage a drill when such passes through said first tube member, said wiper blade being resiliently biassed towards said second position and arranged to engage said first tube member whereby it may be moved to said first position by relative movement between said first and second tube members.

Preferably, two wiper blades are pivotally mounted on diametrically opposite portions of the second tube member and are resiliently urged towards the spiral twist drill bit.

According to another feature of the present invention there is provided an earth drilling rig having a drilling table through which a rotary drive shaft for a drill passes and including a wiper assembly as described above-mounted beneath said table to be concentric with said drive shaft.

In order to achieve a particularly clean and rapid emptying of the drill spiral, it is advantageous to give each wiper member the shape of the drill spiral and to dispose the wiper spirals in interchangeable manner in order that optimum wiping may be achieved for any diameter of drill.

BRIEF DESCRIPTION OF THE DRAWINGS An exemplary embodiment of the present invention will now more particularly be described with reference to the single FIGURE of the accompanying drawing, which shows a wiper assembly, for cleaning spiral twist bits on earth-drilling rigs, embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, the drill table 2 of an earth drilling rig is slidably displaceable along a guide mast l and a hollow tube 3 issecured to the drill table 2. The wiper assembly, which is indicated generally by the reference 4, is adjustably secured on the drill table 2 through an element (not shown) such as for example a chain, rope or hydraulic cylinder, and comprises a guide tube 5, wiper blade spirals 6 and 7 and a support 8. The wiper blade spirals 6 and 7, are mounted in hinged fashion on the guide tube 5 and are connected by a traction spring 9. The tension exerted by the spring 9 can be adjusted by means of chains 10. The wiper device is guided on the tube 3 by means of the guide tube 5 and slides upwardly and downwardly on the guide mast l, for which purpose rollers 11 are provided on the support 8.

When it is intended to wipe the bored out material from the drill spiral, the wiper device 4 is propelled downwardly until it reaches the end of the tube 3. The wiper members 6 and 7 then pivot inwardly in response to the force exerted by the traction springs 9. Subsequently, the drill rod with the drill, which is indicated diagrammatically by the broken lines 12, is raised out of the borehole until the topmost drill spiral bears on the wiper blades 6 and 7.The drill is now rotated until it reaches the position illustrated. In doing so, the bored out material is wiped off the drill by the wiper blades 6 and 7.

A wiper assembly embodying the invention has the advantage that, by virtue of the special construction of the guide, only one torque is transmitted to the guide mast.

A further advantage is that a wiper arrangement, when in the inoperative position (as shown), does not hamper further working, for example lining ofthe-borehole.

We claim:

1. A wiper assembly for cleaning a spiral twist drill bit on an earth-drilling rig, said wiper assembly comprising in combination;

a first cylindrical tube member adapted to be mounted on a drill rig'concentrically with the drill thereof,

a second member,

mounting means for slidably mounting said second member for axial movement along said first tube member, at least one wiper blade pivotally mounted on said second member, each said wiper blade being pivotally displaceable between a first position, wherein each said blade is clear of the bore of said first tube member and engages said first tube member, and a second position wherein each said wiper blade engages said spiral twist drill bit when said drill bit passes through said first tube member,

spring means associated with each said wiper blade to resiliently urge each said wiper blade towards said second position, whereby each said wiper blade is pivotally displaced between said first and second positions in response to a predetermined axial movement of said second member along said first tube member.

2. A wiper assembly as defined in claim I, wherein said second member comprises a second tube member concentrically mounted on said first tube member, and wherein two of said wiper blades are pivotally mounted at points diametrically opposite one another on said second tube member.

3. A wiper assembly as defined in claim 2, comprising a tension spring interconnecting said two wiper blades and resiliently biassing each of said wiper blades towards said second position.

4. A wiper assembly as defined in claim 1, wherein each said wiper blade is formed with a spiral portion to engage with said drill bit.

5. A wiper assembly as defined in claim 4, wherein each spiral portion of said wiper blade has substantially the same spiral shape as said spiral twist drill bit.

6. A wiper assembly as defined in claim 1, comprising at least one roller rotatably mounted on said second member and a guide member, said roller engaging said guide member and being rolled along said guide member when said second member is axially displaced along said first tube member.

7. A drill rig comprising in combination;

a drill table,

a rotary drive shaft passing through said table,

a spiral twist bit mounted on one end ofsaid shaft,

a first cylindrical tube member mounted on the drill table and disposed concentrically with said drive shaft,

21 second member,

slidable mounting means to mount said second member for axial movement along said first tube member,

at least one wiper blade pivotally mounted on said second member, each said wiper blade being pivotally displaceable between a first position, wherein each said blade is clear of the bore of said first tube member and engages said first tube member, and a second position wherein each said blade engages said spiral twist drill bit, spring means associated with each said wiper blade to resiliently urge each said wiper blade towards said second position, displacement means to relatively displace said first and second members along the axis of the first member, each said wiper blade being pivotally displaced by said spring means between said first and second positions when a predetermined relative displacement between said first and second members occurs in response to said displacement means. 8. A drill rig as defined in claim 7, wherein said second member comprises a second tube member concentrically mounted on said first tube member, and wherein two of said wiper blades are pivotally mounted at points diametrically opposite one another on said second tube member.

9. A drill rig as defined in claim 8, comprising a tension spring interconnecting said two wiper blades and resiliently biassing each of said wiper blades towards said second positron.

10. A drill rig as defined in claim 7, wherein each said wiper blade is formed with a spiral portion to engage with said drill.

11. A drill rig as defined in claim 10, wherein each spiral portion of said wiper blade has substantially the same spiral shape as said spiral twist drill bit.

12. A drill bit as defined in claim 7, comprising a drilling mast supporting said drill table and at least one roller rotatably mounted on said second member, said roller engaging said drilling mast and being rolled along said drilling mast when said first and second members are relatively displaced by said displacement means. 

1. A wiper assembly for cleaning a spiral twist drill bit on an earth-drilling rig, said wiper assembly comprising in combination; a first cylindrical tube member adapted to be mounted on a drill rig concentrically with the drill thereof, a second member, mounting means for slidably mounting said second member for axial movement along said first tube member, at least one wiper blade pivotally mounted on said second member, each said wiper blade being pivotally displaceable between a first position, wherein each said blade is clear of the bore of said first tube member and engages said first tube member, and a second position wherein each said wiper blade engages said spiral twist drill bit when said drill bit passes through said first tube member, spring means associated with each said wiper blade to resiliently urge each said wiper blade towards said second position, whereby each said wiper blade is pivotally displaced between said first and second positions in response to a predetermined axial movement of said second member along said first tube member.
 2. A wiper assembly as defined in claim 1, wherein said second member comprises a second tube member concentrically mounted on said first tube member, and wherein two of said wiper blades are pivotally mounted at points diametrically opposite one another on said second tube member.
 3. A wiper assembly as defined in claim 2, comprising a tension spring interconnecting saiD two wiper blades and resiliently biassing each of said wiper blades towards said second position.
 4. A wiper assembly as defined in claim 1, wherein each said wiper blade is formed with a spiral portion to engage with said drill bit.
 5. A wiper assembly as defined in claim 4, wherein each spiral portion of said wiper blade has substantially the same spiral shape as said spiral twist drill bit.
 6. A wiper assembly as defined in claim 1, comprising at least one roller rotatably mounted on said second member and a guide member, said roller engaging said guide member and being rolled along said guide member when said second member is axially displaced along said first tube member.
 7. A drill rig comprising in combination; a drill table, a rotary drive shaft passing through said table, a spiral twist bit mounted on one end of said shaft, a first cylindrical tube member mounted on the drill table and disposed concentrically with said drive shaft, a second member, slidable mounting means to mount said second member for axial movement along said first tube member, at least one wiper blade pivotally mounted on said second member, each said wiper blade being pivotally displaceable between a first position, wherein each said blade is clear of the bore of said first tube member and engages said first tube member, and a second position wherein each said blade engages said spiral twist drill bit, spring means associated with each said wiper blade to resiliently urge each said wiper blade towards said second position, displacement means to relatively displace said first and second members along the axis of the first member, each said wiper blade being pivotally displaced by said spring means between said first and second positions when a predetermined relative displacement between said first and second members occurs in response to said displacement means.
 8. A drill rig as defined in claim 7, wherein said second member comprises a second tube member concentrically mounted on said first tube member, and wherein two of said wiper blades are pivotally mounted at points diametrically opposite one another on said second tube member.
 9. A drill rig as defined in claim 8, comprising a tension spring interconnecting said two wiper blades and resiliently biassing each of said wiper blades towards said second position.
 10. A drill rig as defined in claim 7, wherein each said wiper blade is formed with a spiral portion to engage with said drill.
 11. A drill rig as defined in claim 10, wherein each spiral portion of said wiper blade has substantially the same spiral shape as said spiral twist drill bit.
 12. A drill bit as defined in claim 7, comprising a drilling mast supporting said drill table and at least one roller rotatably mounted on said second member, said roller engaging said drilling mast and being rolled along said drilling mast when said first and second members are relatively displaced by said displacement means. 